//===- opt.cpp - The LLVM Modular Optimizer -------------------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // Optimizations may be specified an arbitrary number of times on the command // line, They are run in the order specified. // //===----------------------------------------------------------------------===// #include "llvm/IR/LLVMContext.h" #include "llvm/ADT/StringSet.h" #include "llvm/ADT/Triple.h" #include "llvm/Analysis/CallGraph.h" #include "llvm/Analysis/CallGraphSCCPass.h" #include "llvm/Analysis/LoopPass.h" #include "llvm/Analysis/RegionPass.h" #include "llvm/Analysis/Verifier.h" #include "llvm/Assembly/PrintModulePass.h" #include "llvm/Bitcode/ReaderWriter.h" #include "llvm/CodeGen/CommandFlags.h" #include "llvm/DebugInfo.h" #include "llvm/IR/DataLayout.h" #include "llvm/IR/Module.h" #include "llvm/IRReader/IRReader.h" #include "llvm/LinkAllIR.h" #include "llvm/LinkAllPasses.h" #include "llvm/MC/SubtargetFeature.h" #include "llvm/PassManager.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ManagedStatic.h" #include "llvm/Support/PassNameParser.h" #include "llvm/Support/PluginLoader.h" #include "llvm/Support/PrettyStackTrace.h" #include "llvm/Support/Signals.h" #include "llvm/Support/SourceMgr.h" #include "llvm/Support/SystemUtils.h" #include "llvm/Support/TargetRegistry.h" #include "llvm/Support/TargetSelect.h" #include "llvm/Support/ToolOutputFile.h" #include "llvm/Target/TargetLibraryInfo.h" #include "llvm/Target/TargetMachine.h" #include "llvm/Transforms/IPO/PassManagerBuilder.h" #include #include using namespace llvm; // The OptimizationList is automatically populated with registered Passes by the // PassNameParser. // static cl::list PassList(cl::desc("Optimizations available:")); // Other command line options... // static cl::opt InputFilename(cl::Positional, cl::desc(""), cl::init("-"), cl::value_desc("filename")); static cl::opt OutputFilename("o", cl::desc("Override output filename"), cl::value_desc("filename")); static cl::opt Force("f", cl::desc("Enable binary output on terminals")); static cl::opt PrintEachXForm("p", cl::desc("Print module after each transformation")); static cl::opt NoOutput("disable-output", cl::desc("Do not write result bitcode file"), cl::Hidden); static cl::opt OutputAssembly("S", cl::desc("Write output as LLVM assembly")); static cl::opt NoVerify("disable-verify", cl::desc("Do not verify result module"), cl::Hidden); static cl::opt VerifyEach("verify-each", cl::desc("Verify after each transform")); static cl::opt StripDebug("strip-debug", cl::desc("Strip debugger symbol info from translation unit")); static cl::opt DisableInline("disable-inlining", cl::desc("Do not run the inliner pass")); static cl::opt DisableOptimizations("disable-opt", cl::desc("Do not run any optimization passes")); static cl::opt DisableInternalize("disable-internalize", cl::desc("Do not mark all symbols as internal")); static cl::opt StandardCompileOpts("std-compile-opts", cl::desc("Include the standard compile time optimizations")); static cl::opt StandardLinkOpts("std-link-opts", cl::desc("Include the standard link time optimizations")); static cl::opt OptLevelO1("O1", cl::desc("Optimization level 1. Similar to clang -O1")); static cl::opt OptLevelO2("O2", cl::desc("Optimization level 2. Similar to clang -O2")); static cl::opt OptLevelOs("Os", cl::desc("Like -O2 with extra optimizations for size. Similar to clang -Os")); static cl::opt OptLevelOz("Oz", cl::desc("Like -Os but reduces code size further. Similar to clang -Oz")); static cl::opt OptLevelO3("O3", cl::desc("Optimization level 3. Similar to clang -O3")); static cl::opt TargetTriple("mtriple", cl::desc("Override target triple for module")); static cl::opt UnitAtATime("funit-at-a-time", cl::desc("Enable IPO. This is same as llvm-gcc's -funit-at-a-time"), cl::init(true)); static cl::opt DisableSimplifyLibCalls("disable-simplify-libcalls", cl::desc("Disable simplify-libcalls")); static cl::opt Quiet("q", cl::desc("Obsolete option"), cl::Hidden); static cl::alias QuietA("quiet", cl::desc("Alias for -q"), cl::aliasopt(Quiet)); static cl::opt AnalyzeOnly("analyze", cl::desc("Only perform analysis, no optimization")); static cl::opt PrintBreakpoints("print-breakpoints-for-testing", cl::desc("Print select breakpoints location for testing")); static cl::opt DefaultDataLayout("default-data-layout", cl::desc("data layout string to use if not specified by module"), cl::value_desc("layout-string"), cl::init("")); // ---------- Define Printers for module and function passes ------------ namespace { struct CallGraphSCCPassPrinter : public CallGraphSCCPass { static char ID; const PassInfo *PassToPrint; raw_ostream &Out; std::string PassName; CallGraphSCCPassPrinter(const PassInfo *PI, raw_ostream &out) : CallGraphSCCPass(ID), PassToPrint(PI), Out(out) { std::string PassToPrintName = PassToPrint->getPassName(); PassName = "CallGraphSCCPass Printer: " + PassToPrintName; } virtual bool runOnSCC(CallGraphSCC &SCC) { if (!Quiet) Out << "Printing analysis '" << PassToPrint->getPassName() << "':\n"; // Get and print pass... for (CallGraphSCC::iterator I = SCC.begin(), E = SCC.end(); I != E; ++I) { Function *F = (*I)->getFunction(); if (F) getAnalysisID(PassToPrint->getTypeInfo()).print(Out, F->getParent()); } return false; } virtual const char *getPassName() const { return PassName.c_str(); } virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.addRequiredID(PassToPrint->getTypeInfo()); AU.setPreservesAll(); } }; char CallGraphSCCPassPrinter::ID = 0; struct ModulePassPrinter : public ModulePass { static char ID; const PassInfo *PassToPrint; raw_ostream &Out; std::string PassName; ModulePassPrinter(const PassInfo *PI, raw_ostream &out) : ModulePass(ID), PassToPrint(PI), Out(out) { std::string PassToPrintName = PassToPrint->getPassName(); PassName = "ModulePass Printer: " + PassToPrintName; } virtual bool runOnModule(Module &M) { if (!Quiet) Out << "Printing analysis '" << PassToPrint->getPassName() << "':\n"; // Get and print pass... getAnalysisID(PassToPrint->getTypeInfo()).print(Out, &M); return false; } virtual const char *getPassName() const { return PassName.c_str(); } virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.addRequiredID(PassToPrint->getTypeInfo()); AU.setPreservesAll(); } }; char ModulePassPrinter::ID = 0; struct FunctionPassPrinter : public FunctionPass { const PassInfo *PassToPrint; raw_ostream &Out; static char ID; std::string PassName; FunctionPassPrinter(const PassInfo *PI, raw_ostream &out) : FunctionPass(ID), PassToPrint(PI), Out(out) { std::string PassToPrintName = PassToPrint->getPassName(); PassName = "FunctionPass Printer: " + PassToPrintName; } virtual bool runOnFunction(Function &F) { if (!Quiet) Out << "Printing analysis '" << PassToPrint->getPassName() << "' for function '" << F.getName() << "':\n"; // Get and print pass... getAnalysisID(PassToPrint->getTypeInfo()).print(Out, F.getParent()); return false; } virtual const char *getPassName() const { return PassName.c_str(); } virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.addRequiredID(PassToPrint->getTypeInfo()); AU.setPreservesAll(); } }; char FunctionPassPrinter::ID = 0; struct LoopPassPrinter : public LoopPass { static char ID; const PassInfo *PassToPrint; raw_ostream &Out; std::string PassName; LoopPassPrinter(const PassInfo *PI, raw_ostream &out) : LoopPass(ID), PassToPrint(PI), Out(out) { std::string PassToPrintName = PassToPrint->getPassName(); PassName = "LoopPass Printer: " + PassToPrintName; } virtual bool runOnLoop(Loop *L, LPPassManager &LPM) { if (!Quiet) Out << "Printing analysis '" << PassToPrint->getPassName() << "':\n"; // Get and print pass... getAnalysisID(PassToPrint->getTypeInfo()).print(Out, L->getHeader()->getParent()->getParent()); return false; } virtual const char *getPassName() const { return PassName.c_str(); } virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.addRequiredID(PassToPrint->getTypeInfo()); AU.setPreservesAll(); } }; char LoopPassPrinter::ID = 0; struct RegionPassPrinter : public RegionPass { static char ID; const PassInfo *PassToPrint; raw_ostream &Out; std::string PassName; RegionPassPrinter(const PassInfo *PI, raw_ostream &out) : RegionPass(ID), PassToPrint(PI), Out(out) { std::string PassToPrintName = PassToPrint->getPassName(); PassName = "RegionPass Printer: " + PassToPrintName; } virtual bool runOnRegion(Region *R, RGPassManager &RGM) { if (!Quiet) { Out << "Printing analysis '" << PassToPrint->getPassName() << "' for " << "region: '" << R->getNameStr() << "' in function '" << R->getEntry()->getParent()->getName() << "':\n"; } // Get and print pass... getAnalysisID(PassToPrint->getTypeInfo()).print(Out, R->getEntry()->getParent()->getParent()); return false; } virtual const char *getPassName() const { return PassName.c_str(); } virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.addRequiredID(PassToPrint->getTypeInfo()); AU.setPreservesAll(); } }; char RegionPassPrinter::ID = 0; struct BasicBlockPassPrinter : public BasicBlockPass { const PassInfo *PassToPrint; raw_ostream &Out; static char ID; std::string PassName; BasicBlockPassPrinter(const PassInfo *PI, raw_ostream &out) : BasicBlockPass(ID), PassToPrint(PI), Out(out) { std::string PassToPrintName = PassToPrint->getPassName(); PassName = "BasicBlockPass Printer: " + PassToPrintName; } virtual bool runOnBasicBlock(BasicBlock &BB) { if (!Quiet) Out << "Printing Analysis info for BasicBlock '" << BB.getName() << "': Pass " << PassToPrint->getPassName() << ":\n"; // Get and print pass... getAnalysisID(PassToPrint->getTypeInfo()).print(Out, BB.getParent()->getParent()); return false; } virtual const char *getPassName() const { return PassName.c_str(); } virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.addRequiredID(PassToPrint->getTypeInfo()); AU.setPreservesAll(); } }; char BasicBlockPassPrinter::ID = 0; struct BreakpointPrinter : public ModulePass { raw_ostream &Out; static char ID; BreakpointPrinter(raw_ostream &out) : ModulePass(ID), Out(out) { } void getContextName(DIDescriptor Context, std::string &N) { if (Context.isNameSpace()) { DINameSpace NS(Context); if (!NS.getName().empty()) { getContextName(NS.getContext(), N); N = N + NS.getName().str() + "::"; } } else if (Context.isType()) { DIType TY(Context); if (!TY.getName().empty()) { getContextName(TY.getContext(), N); N = N + TY.getName().str() + "::"; } } } virtual bool runOnModule(Module &M) { StringSet<> Processed; if (NamedMDNode *NMD = M.getNamedMetadata("llvm.dbg.sp")) for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) { std::string Name; DISubprogram SP(NMD->getOperand(i)); if (SP.Verify()) getContextName(SP.getContext(), Name); Name = Name + SP.getDisplayName().str(); if (!Name.empty() && Processed.insert(Name)) { Out << Name << "\n"; } } return false; } virtual void getAnalysisUsage(AnalysisUsage &AU) const { AU.setPreservesAll(); } }; } // anonymous namespace char BreakpointPrinter::ID = 0; static inline void addPass(PassManagerBase &PM, Pass *P) { // Add the pass to the pass manager... PM.add(P); // If we are verifying all of the intermediate steps, add the verifier... if (VerifyEach) PM.add(createVerifierPass()); } /// AddOptimizationPasses - This routine adds optimization passes /// based on selected optimization level, OptLevel. This routine /// duplicates llvm-gcc behaviour. /// /// OptLevel - Optimization Level static void AddOptimizationPasses(PassManagerBase &MPM,FunctionPassManager &FPM, unsigned OptLevel, unsigned SizeLevel) { FPM.add(createVerifierPass()); // Verify that input is correct PassManagerBuilder Builder; Builder.OptLevel = OptLevel; Builder.SizeLevel = SizeLevel; if (DisableInline) { // No inlining pass } else if (OptLevel > 1) { unsigned Threshold = 225; if (SizeLevel == 1) // -Os Threshold = 75; else if (SizeLevel == 2) // -Oz Threshold = 25; if (OptLevel > 2) Threshold = 275; Builder.Inliner = createFunctionInliningPass(Threshold); } else { Builder.Inliner = createAlwaysInlinerPass(); } Builder.DisableUnitAtATime = !UnitAtATime; Builder.DisableUnrollLoops = OptLevel == 0; Builder.populateFunctionPassManager(FPM); Builder.populateModulePassManager(MPM); } static void AddStandardCompilePasses(PassManagerBase &PM) { PM.add(createVerifierPass()); // Verify that input is correct // If the -strip-debug command line option was specified, do it. if (StripDebug) addPass(PM, createStripSymbolsPass(true)); if (DisableOptimizations) return; // -std-compile-opts adds the same module passes as -O3. PassManagerBuilder Builder; if (!DisableInline) Builder.Inliner = createFunctionInliningPass(); Builder.OptLevel = 3; Builder.populateModulePassManager(PM); } static void AddStandardLinkPasses(PassManagerBase &PM) { PM.add(createVerifierPass()); // Verify that input is correct // If the -strip-debug command line option was specified, do it. if (StripDebug) addPass(PM, createStripSymbolsPass(true)); if (DisableOptimizations) return; PassManagerBuilder Builder; Builder.populateLTOPassManager(PM, /*Internalize=*/ !DisableInternalize, /*RunInliner=*/ !DisableInline); } //===----------------------------------------------------------------------===// // CodeGen-related helper functions. // static TargetOptions GetTargetOptions() { TargetOptions Options; Options.LessPreciseFPMADOption = EnableFPMAD; Options.NoFramePointerElim = DisableFPElim; Options.NoFramePointerElimNonLeaf = DisableFPElimNonLeaf; Options.AllowFPOpFusion = FuseFPOps; Options.UnsafeFPMath = EnableUnsafeFPMath; Options.NoInfsFPMath = EnableNoInfsFPMath; Options.NoNaNsFPMath = EnableNoNaNsFPMath; Options.HonorSignDependentRoundingFPMathOption = EnableHonorSignDependentRoundingFPMath; Options.UseSoftFloat = GenerateSoftFloatCalls; if (FloatABIForCalls != FloatABI::Default) Options.FloatABIType = FloatABIForCalls; Options.NoZerosInBSS = DontPlaceZerosInBSS; Options.GuaranteedTailCallOpt = EnableGuaranteedTailCallOpt; Options.DisableTailCalls = DisableTailCalls; Options.StackAlignmentOverride = OverrideStackAlignment; Options.RealignStack = EnableRealignStack; Options.TrapFuncName = TrapFuncName; Options.PositionIndependentExecutable = EnablePIE; Options.EnableSegmentedStacks = SegmentedStacks; Options.UseInitArray = UseInitArray; Options.SSPBufferSize = SSPBufferSize; return Options; } CodeGenOpt::Level GetCodeGenOptLevel() { if (OptLevelO1) return CodeGenOpt::Less; if (OptLevelO2) return CodeGenOpt::Default; if (OptLevelO3) return CodeGenOpt::Aggressive; return CodeGenOpt::None; } // Returns the TargetMachine instance or zero if no triple is provided. static TargetMachine* GetTargetMachine(Triple TheTriple) { std::string Error; const Target *TheTarget = TargetRegistry::lookupTarget(MArch, TheTriple, Error); // Some modules don't specify a triple, and this is okay. if (!TheTarget) { return 0; } // Package up features to be passed to target/subtarget std::string FeaturesStr; if (MAttrs.size()) { SubtargetFeatures Features; for (unsigned i = 0; i != MAttrs.size(); ++i) Features.AddFeature(MAttrs[i]); FeaturesStr = Features.getString(); } return TheTarget->createTargetMachine(TheTriple.getTriple(), MCPU, FeaturesStr, GetTargetOptions(), RelocModel, CMModel, GetCodeGenOptLevel()); } //===----------------------------------------------------------------------===// // main for opt // int main(int argc, char **argv) { sys::PrintStackTraceOnErrorSignal(); llvm::PrettyStackTraceProgram X(argc, argv); // Enable debug stream buffering. EnableDebugBuffering = true; llvm_shutdown_obj Y; // Call llvm_shutdown() on exit. LLVMContext &Context = getGlobalContext(); InitializeAllTargets(); InitializeAllTargetMCs(); // Initialize passes PassRegistry &Registry = *PassRegistry::getPassRegistry(); initializeCore(Registry); initializeDebugIRPass(Registry); initializeScalarOpts(Registry); initializeObjCARCOpts(Registry); initializeVectorization(Registry); initializeIPO(Registry); initializeAnalysis(Registry); initializeIPA(Registry); initializeTransformUtils(Registry); initializeInstCombine(Registry); initializeInstrumentation(Registry); initializeTarget(Registry); cl::ParseCommandLineOptions(argc, argv, "llvm .bc -> .bc modular optimizer and analysis printer\n"); if (AnalyzeOnly && NoOutput) { errs() << argv[0] << ": analyze mode conflicts with no-output mode.\n"; return 1; } SMDiagnostic Err; // Load the input module... OwningPtr M; M.reset(ParseIRFile(InputFilename, Err, Context)); if (M.get() == 0) { Err.print(argv[0], errs()); return 1; } // If we are supposed to override the target triple, do so now. if (!TargetTriple.empty()) M->setTargetTriple(Triple::normalize(TargetTriple)); // Figure out what stream we are supposed to write to... OwningPtr Out; if (NoOutput) { if (!OutputFilename.empty()) errs() << "WARNING: The -o (output filename) option is ignored when\n" "the --disable-output option is used.\n"; } else { // Default to standard output. if (OutputFilename.empty()) OutputFilename = "-"; std::string ErrorInfo; Out.reset(new tool_output_file(OutputFilename.c_str(), ErrorInfo, raw_fd_ostream::F_Binary)); if (!ErrorInfo.empty()) { errs() << ErrorInfo << '\n'; return 1; } } // If the output is set to be emitted to standard out, and standard out is a // console, print out a warning message and refuse to do it. We don't // impress anyone by spewing tons of binary goo to a terminal. if (!Force && !NoOutput && !AnalyzeOnly && !OutputAssembly) if (CheckBitcodeOutputToConsole(Out->os(), !Quiet)) NoOutput = true; // Create a PassManager to hold and optimize the collection of passes we are // about to build. // PassManager Passes; // Add an appropriate TargetLibraryInfo pass for the module's triple. TargetLibraryInfo *TLI = new TargetLibraryInfo(Triple(M->getTargetTriple())); // The -disable-simplify-libcalls flag actually disables all builtin optzns. if (DisableSimplifyLibCalls) TLI->disableAllFunctions(); Passes.add(TLI); // Add an appropriate DataLayout instance for this module. DataLayout *TD = 0; const std::string &ModuleDataLayout = M.get()->getDataLayout(); if (!ModuleDataLayout.empty()) TD = new DataLayout(ModuleDataLayout); else if (!DefaultDataLayout.empty()) TD = new DataLayout(DefaultDataLayout); if (TD) Passes.add(TD); Triple ModuleTriple(M->getTargetTriple()); TargetMachine *Machine = 0; if (ModuleTriple.getArch()) Machine = GetTargetMachine(Triple(ModuleTriple)); OwningPtr TM(Machine); // Add internal analysis passes from the target machine. if (TM.get()) TM->addAnalysisPasses(Passes); OwningPtr FPasses; if (OptLevelO1 || OptLevelO2 || OptLevelOs || OptLevelOz || OptLevelO3) { FPasses.reset(new FunctionPassManager(M.get())); if (TD) FPasses->add(new DataLayout(*TD)); } if (PrintBreakpoints) { // Default to standard output. if (!Out) { if (OutputFilename.empty()) OutputFilename = "-"; std::string ErrorInfo; Out.reset(new tool_output_file(OutputFilename.c_str(), ErrorInfo, raw_fd_ostream::F_Binary)); if (!ErrorInfo.empty()) { errs() << ErrorInfo << '\n'; return 1; } } Passes.add(new BreakpointPrinter(Out->os())); NoOutput = true; } // If the -strip-debug command line option was specified, add it. If // -std-compile-opts was also specified, it will handle StripDebug. if (StripDebug && !StandardCompileOpts) addPass(Passes, createStripSymbolsPass(true)); // Create a new optimization pass for each one specified on the command line for (unsigned i = 0; i < PassList.size(); ++i) { // Check to see if -std-compile-opts was specified before this option. If // so, handle it. if (StandardCompileOpts && StandardCompileOpts.getPosition() < PassList.getPosition(i)) { AddStandardCompilePasses(Passes); StandardCompileOpts = false; } if (StandardLinkOpts && StandardLinkOpts.getPosition() < PassList.getPosition(i)) { AddStandardLinkPasses(Passes); StandardLinkOpts = false; } if (OptLevelO1 && OptLevelO1.getPosition() < PassList.getPosition(i)) { AddOptimizationPasses(Passes, *FPasses, 1, 0); OptLevelO1 = false; } if (OptLevelO2 && OptLevelO2.getPosition() < PassList.getPosition(i)) { AddOptimizationPasses(Passes, *FPasses, 2, 0); OptLevelO2 = false; } if (OptLevelOs && OptLevelOs.getPosition() < PassList.getPosition(i)) { AddOptimizationPasses(Passes, *FPasses, 2, 1); OptLevelOs = false; } if (OptLevelOz && OptLevelOz.getPosition() < PassList.getPosition(i)) { AddOptimizationPasses(Passes, *FPasses, 2, 2); OptLevelOz = false; } if (OptLevelO3 && OptLevelO3.getPosition() < PassList.getPosition(i)) { AddOptimizationPasses(Passes, *FPasses, 3, 0); OptLevelO3 = false; } const PassInfo *PassInf = PassList[i]; Pass *P = 0; if (PassInf->getNormalCtor()) P = PassInf->getNormalCtor()(); else errs() << argv[0] << ": cannot create pass: " << PassInf->getPassName() << "\n"; if (P) { PassKind Kind = P->getPassKind(); addPass(Passes, P); if (AnalyzeOnly) { switch (Kind) { case PT_BasicBlock: Passes.add(new BasicBlockPassPrinter(PassInf, Out->os())); break; case PT_Region: Passes.add(new RegionPassPrinter(PassInf, Out->os())); break; case PT_Loop: Passes.add(new LoopPassPrinter(PassInf, Out->os())); break; case PT_Function: Passes.add(new FunctionPassPrinter(PassInf, Out->os())); break; case PT_CallGraphSCC: Passes.add(new CallGraphSCCPassPrinter(PassInf, Out->os())); break; default: Passes.add(new ModulePassPrinter(PassInf, Out->os())); break; } } } if (PrintEachXForm) Passes.add(createPrintModulePass(&errs())); } // If -std-compile-opts was specified at the end of the pass list, add them. if (StandardCompileOpts) { AddStandardCompilePasses(Passes); StandardCompileOpts = false; } if (StandardLinkOpts) { AddStandardLinkPasses(Passes); StandardLinkOpts = false; } if (OptLevelO1) AddOptimizationPasses(Passes, *FPasses, 1, 0); if (OptLevelO2) AddOptimizationPasses(Passes, *FPasses, 2, 0); if (OptLevelOs) AddOptimizationPasses(Passes, *FPasses, 2, 1); if (OptLevelOz) AddOptimizationPasses(Passes, *FPasses, 2, 2); if (OptLevelO3) AddOptimizationPasses(Passes, *FPasses, 3, 0); if (OptLevelO1 || OptLevelO2 || OptLevelOs || OptLevelOz || OptLevelO3) { FPasses->doInitialization(); for (Module::iterator F = M->begin(), E = M->end(); F != E; ++F) FPasses->run(*F); FPasses->doFinalization(); } // Check that the module is well formed on completion of optimization if (!NoVerify && !VerifyEach) Passes.add(createVerifierPass()); // Write bitcode or assembly to the output as the last step... if (!NoOutput && !AnalyzeOnly) { if (OutputAssembly) Passes.add(createPrintModulePass(&Out->os())); else Passes.add(createBitcodeWriterPass(Out->os())); } // Before executing passes, print the final values of the LLVM options. cl::PrintOptionValues(); // Now that we have all of the passes ready, run them. Passes.run(*M.get()); // Declare success. if (!NoOutput || PrintBreakpoints) Out->keep(); return 0; }